1. Field of the Invention
The present invention relates to a connector suitable for use in an electrically-operated power steering system of an automobile, and a turning angle sensor using the connector.
2. Description of the Related Art
In a conventional turning angle sensor, a rotating drum 2 consisting of a disk-like magnetic body is fixedly mounted on a rotating shaft 1 as shown in FIG. 12. The rotating drum 2 is provided with magnetic codes formed of a plurality of magnetic poles (N-S) all around the perimeter.
On the perimeter of the rotating drum 2, magnetic sensors 4 are arranged at specific intervals P, thereby forming the conventional turning angle sensor.
The conventional turning angle sensor is of such a design that when the rotating shaft 1 is turned to turn the rotating drum 2, the magnetic sensor 4 detects analog changes in the magnetic force of the plurality of magnetic poles, thus enabling the detection of the turning angle of the rotating drum 2.
The conventional turning angle sensor stated above is used for instance in an electrically-operated power steering system of an automobile, which will be explained below. As shown in FIG. 13, the rotating shaft 1 is comprised of a driving shaft 1a and a load shaft 1b, which are coupled with a torsion bar T, so that when the driving shaft 1a is turned, the load shaft 1b is also turned through the torsion bar T.
On the driving shaft 1a and the load shaft 1b thus coupled, two rotating drums 2 and 3 are fixedly mounted near their ends at a spacing L.
On the perimeter of the rotating drums 2 and 3, a pair of magnetic sensors 4 and 5 are arranged at specific intervals P1 and P2, thereby forming the conventional turning angle sensor.
The rotating shaft 1 thus mounted with the conventional turning angle sensor can turn the load shaft 1b from the driving shaft 1a through the torsion bar T by applying a greater torque than the load torque being exerted to the load shaft 1b side to the driving shaft 1a which is formed integrally with a steering wheel.
With the turning of the rotating shaft 1, the load shaft 1b side is turned with a slight delay in relation to the driving shaft 1a side by the torsion bar T.
Because of the delay of rotation of the load shaft 1b side there takes place a difference in the angle of rotation between the driving shaft 1a side and the load shaft 1b side. The difference in the angle of rotation is proportional to a difference between the load torque and the rotational torque of the driving shaft 1a, that is, to a torque between these two shafts. The difference in the rotational angle increases with an increase in the torque between the two shafts, and reversely decreases with a decrease in the torque between the two shafts.
According to the conventional turning angle sensor, the turning angle is detected on either side of the driving shaft 1a and the load shaft 1b respectively to determine a difference in the turning angle, and then a torque between the load shaft 1b and the driving shaft 1a is measured to determine an assist power to be added to the load shaft 1b. 
In the conventional turning angle sensor, however, the rotating drums 2 and 3 are directly fixedly mounted on the driving shaft 1a and the load shaft 1b, presenting such problems as troublesome rotating drum mounting operation and low producibility.
To solve the problems, a spring member not shown is interposed between the driving shaft 1a and the rotating drum 2 and between the load shaft 1b and the rotating drum 3, thereby facilitating assembling of the rotating drums 2 and 3 to the driving shaft 1a and the load shaft 1b. In this case, however, the transmission of rotation from the driving shaft 1a and the load shaft 1b to the rotating drums 2 and 3 by means of the spring member is not effectively done, resulting in improper transmission of rotation from the driving shaft 1a and the load shaft 1b to the rotating drums 2 and 3.
The present invention provides, as a first means to solve the above-described problem, the connector including a metal plate for frictional engagement between the rotating shaft and the rotating body in the center part of which the rotating shaft is inserted, to turn the rotating body together with the rotating shaft. The connector has a ring-like base, a plurality of springs extended from the base and having a bent portion, and a hole in the top of the bent portion.
As a second means to solve the above-described problem, the connector has a rectangular hole in the top of the bent portion.
As a third means to solve the above-described problem, there is provided the connector having the spring formed by bending the base approximately squarely; the bent portion with the hole being formed wider than the root of the bent portion of the spring.
As a fourth means to solve the above-described problem, the connector has a condition such that the hole formed is located at the center in the direction of width of the bent portion.
Furthermore, as a fifth means to solve the above-described problem, the turning angle sensor comprises a connecting portion which includes the rotating body for driving the magnets, the rotating shaft inserted at the center of the rotating body, and the metal plate attached on the rotating body to turn the rotating body together with the rotation of the rotating shaft with the rotating body held in frictional engagement with the rotating shaft. The connecting portion has the ring-like base, a plurality of springs extended from the base and having the bent portion, and a hole provided in the top of the bent portion; the base being attached to the rotating body to hold the peripheral edge of the hole in frictional engagement with the rotating shaft by the force of the spring.
Furthermore, as a sixth means to solve the above-described problem of the turning angle sensor the hole provided in the top of the bent portion is formed rectangular, and the peripheral edge of the rectangular hole is held in frictional engagement with the rotating shaft.
Furthermore, as a seventh means to solve the above-described problem the spring of the turning angle sensor is formed by bending approximately squarely at the base; and the bent portion having the hole is made wider than the bent base of the spring.
Furthermore, as an eighth means to solve the above-described problem the hole of the turning angle sensor is formed at the center of the width of the bent portion.